1. Field of the Invention
The present invention relates to thin film transistors (TFTs), and in particular to a TFT, its manufacturing method, and a display device employing the TFTs.
2. The Related Arts
Flat panel displays are widely popular in recent years and liquid crystal displays (LCDs) are the mainstream of flat panel displays due to their high space efficiency, low power consumption, no radiation, and low electromagnetic interference.
TFTs are commonly applied to LCDs as switch elements. An important indicator to the quality of TFTs as switch elements is the severity of erroneous write when charging/discharging TFTs, and this is related to the parasitic capacitance Cgs between gate and source electrodes. When a TFT is turned on or off, the gate voltage Vgs drops instantly from a high level Vgon to a low level Vgoff, the variation ΔVgs of Vgs is coupled to the pixel electrode by the parasitic capacitance Cgs, causing pixel voltage Vp to vary for an amount ΔVp. ΔVp would be bigger as the parasitic capacitance Cgs is larger.